Cushioned handle for tools



Oct. 27, 1936. F. P. FoRss CUSHIONED HANDLE FOR TOOLS Filed Deo. 23, 1955 1 D INVENTOR. Fmr/#0f f? Fo/Pss ATTORNEYS Patented Oct. 27, 1936 UNITED STATES PATENT OFFICE cUsHIoNED HANDLE Foa Toons Application December 23, 1935, Serial No. 55,729

8 Claims.

This invention relates to cushion means for the handles of portable power actuated impact tools such as riveting hammers, chipping hammers, and the like to absorb the vibrations to which the barrels of these tools are subjected when in use, and thus relieve the hand of the operator grasping the handle of the tool of such vibrations and their resultant fatigue and sting.

The cushion member, in accordance with my invention, comprises a solid mass of resilient material such as live rubber vulcanized or otherwise interconnected to certain of the parts of the handle assembly and in this connection it is one of the main objects of my invention to so form the handle assembly that only a few of its parts need be handled in the vulcanizing operation. Thus the latter is simplified, as it is only necessary to handle those parts of the handle assembly to which the cushion member is directly connected.

A further object of my invention is to provide a metal surface between the cushion member and the pressure fluid conveying member which extends through the cushion member to prevent metal to metal contact between the handle parts when the hand grasping section of the handle assemblyis bent or deected out of axial alignment with the barrel of the tool and also to prevent chafing and wear on the cushion member in the relative movement of the handle parts.

A further object of my invention is to provide the cushion member with an integral ange portion as a backing for said metal wear surface to cushion axial bending of the hand grasping portion of the handle and thus relieve the main cushion member of side strains.

A further object of my invention is to provide an oil seal to prevent the cushion member from being damaged or injured by lubricant in the barrel or carried into the barrel of the tool with the incoming pressure fluid.

The invention consists further in the features hereinafter described and claimed.

In the accompanying drawing:

Fig. 1 is a longitudinal sectional view with parts in elevation of a, pneumatic hammer provided with a cushioned handle in accordance with my invention;

Fig. 2 is an elevational view of the portion of the handle adjacent the cushion;

Fig. 3 is a cross sectional view taken on line 3-3 of Fig. 1; and

Fig. 4 is a perspective view of the cushion member.

In the-drawing, I indicates the barrel of the tool and 2 indicates the piston or impact element reciprocably mounted in the barrel. 3 indicates the valve block at the inner end of the barrel. Said valve block seats against the end of the barrel and is keyed thereto by one or more dowel pins 4 as shown. The block contains a plate valve 5 for controlling the supply of pressure fluid such as compressed air to the opposite ends of the barrel to reciprocate the piston 2. The porting arrangement in the valve block and in the barrel and the operation of the plate valve are similar to that disclosed in the Reinhold A. Norling Patent No. 1,881,886 granted October 11, 1932. As in said patent, the plate valve is shifted laterally in a chamber in the block by the action of the pressure fluid on its opposite sides to open and close the ports to the opposite ends of the barrel. The piston 2 is driven against a chisel or other work element 6 at the front end of the barrel and supported therein by the usual bushing 'I as shown.

The handle for the tool is secured to the rear end of the barrel and comprises a coupling section 8 and a hand grasping sectionS. The coupling section 8 is in the form of a cap having a tubular or sleeve-like portion IIl which ts over the rear end of the barrel and has screw threaded connection therewith as at II. This connection comprises internal screw threads in the sleeve Ill and external screw threads on the barrel I.

-A lock is employed at the forward end of the sleeve I to hold the handle assembly against rotation after being clamped on the barrel. The lock may comprise a ring I2 slidably, but nonrotatably, fitted on the barrel beyond the sleeve I0 and having teeth to interlock with teeth on the front end of the sleeve. A spring clip I3 engages the ring and the sleeve to hold their teeth interlocked.

The coupling section 8 encloses the valve block 3 and hasan end wall I4 providing a shoulder I5 for direct contact with the valve block as shown. Thus the valve block may be tightly and solidly clamped against the barrel end by the coupling section 8 when the latter is screwed tightly on the barrel. The metal to metal contact between the parts prevents leakage of the pressure fluid between them.

The cushioning means in accordance with my invention, comprises a relatively flat ring or annulus l5 of solid resilient material such as live rubber. The member I6 is incorporated in the handle construction between the coupling section 8 and an auxiliary section I1. The latter has an externally screw threaded hollow lug or projection I8 for connection with the hand grasping section 9 as shown. The section 9 has a threaded opening I9 to receive the lug I8. The opening I 9 extends completely through the portion of the section 9 to which the section I1 is clamped and crosses the pressure fluid supply passage 20 therein as shown. A plug 2| is employed to key the handle section 9 to the lug |8 to hold these parts against rotation when assembled.

The cushion member I6 seats against the opposed, preferably flat surfaces of the handle sections 8 and |'I and is vulcanized thereto to secure these parts together. This connection is made before the handle assembly is applied to the barrel I and before all of the handle sections are assembled in handle forming relation. Thus only the handle sections 8 and and the associated cushion member I6 need be handled in the vulcanizing operation and the latter can thus be performed with the least number of handle parts. This simplifies and reduces the cost of the vulcanizing operation and avoids the necessity of handling or making provision to accommodate any of the handle parts not essential to securing the cushion member |6in place. Thus the larger hand grasping section 9 is not included in the Vulcanizing operation and the parts 8, I6, and |1 may be connected together as a separate unit. This facilitates the manufacture and assembly of the handle fixture and enables the cushion member to be incorporated therein with the least possible expense.

The cushion member I6 is provided with a depending ring-like flange 22. Said flange is integral with the cushion member I6 and iits in a central opening 23 in the end wall I4 of the coupling section 3. The iiange 22 is vulcanized to the wall of the opening 23 when vulcanizing the cushion member to the sections 8 and The flange 22 is offset laterally from the central opening 24 in the cushion member to provide a recess for a metal ring 25 which preferably covers the inner surface of the flange 22 and is substantially flush with the wall of the opening 24 in the cushion member. The ring 25 is also Vulcanized in place when vulcanizing the cushion member to the sections 8 and A tubular member 26 is pressed into the assembly after the cushion member I6 and the ring 25 have been vulcanized in place. The member 2S has a tight fit in the lug I8 and extends from adjacent the closed upper end of the lug above the passage 26 to the metal ring 25, passing through the opening 24 in the cushion member I6 as shown. The opening 24 is larger in diameter than the member 26 and the cushion member I6 is exposed on the outer side of the tool for lateral expansion under compression in opposite directions.

The member 26 extends into the ring 25 to convey the pressure fluid from the handle section 9 to the barrel of the tool and to compress the flange 22 on the cushion member I6 in response to bending the section 9 out of axial alignment with the barrel I. Thus the cushion member I6 is relieved of side strains without reducing its cushioning effect and metal to metal contact with the lower end of the member 26 and chang or wearing of the cushion flange is prevented in the relative movement of the handle parts in response to a compression of the cushion member I6 by vibrations or axial bending of the section 9.

After the handle parts have been assembled a passage 2'| is drilled into the handle section 9 in alignment with the supply passage 20 and The plug 2| is inserted into the passage 21l and into the port 29 to key the lug I8 to the handle section 9 whereupon a screw plug 3| is l screwed into the passage 21 to hold the key plug in place.

A sealing ring 32 of synthetic rubber overlaps the lower ends of the cushion flange 22 and the metal wear ring 25 to prevent lubricant in the barrel or entering with the incoming pressure iiuid reaching the cushion member I6 to deteriorate or injure it. The sealing ring 32 Vis seated in an annular groove or recess 33 in the upper surface of the valve block 3 as shown in Fig. 1. The sealing ring is clamped against the flange 22 and the ring 25 when the handle assembly is clamped on the barrel.

The cushion member I6 as well as the adjacent portion of the handle section and the upper part of the sleeve I8 are made substantially hexagonal in shape as shown in Figs. 2 and 3. Thev purpose of this is to provide means by which the section Il may be held by a wrench or in a vice while being screwed into the handle section 9. Similarly the sleeve I0 can be held when assembling and disassembling the barrel I. Thus the cushion member is not strained or distorted when applying or removing the handle section 9 and barrel I, respectively. Instead of a hexagonal contour, any other desired non-circular shape may be employed.

The handle section 9 has a nipple 34 or equivaient fixture forconnecting the tool to a source of pressure iiuid supply. Also the handle section 9 contains a throttle valve (not shown) for controlling the ow of pressure fluid through the handle to the tool. A trigger 35 is incorporated in the handle to control the opening and closing of the throttle valve.

The tubular member 26 registers with the main inlet port 36 in the valve block 3 so as to supply pressure fluid directly to the valve block. Moreover the valve block is spaced inward from the adjacent portion of the sleeve I0 to provide an exhaust chamber 37 which connects with the atmosphere through one or more exhaust ports 38 in the sleeve i8. The barrel I has exhaust ports and passages connected with the chamber 31 as shown.

The cushion member I6 spaces the members 8 and Il and completely fills all portions of this space occupied by the cushion member. The latter being of resilient material and solid throughout effectively absorbs and dampens vibrations to which the barrel is subjected in the operation Thus these vibrations are not transof the tool. ferred to the handle section 9 and the hand of the operator grasping said section in the use of the is able to effectively respond to the vibrations referred to to dampen and absorb them. The cushion ange 22l takes care of any bending or twisting of the handle section 9 out of axial alignment with the barrel I and thus relieves the main cushion member I6 of side strains without reducing its cushion effect.

The details of construction and arrangement of parts shown and described may be variously changed and modied without departing from the spirit and scope of my invention, except as pointed out in the appended claims.

I claim as my invention:

1. In a portable pneumatic hammer having a barrel, a cushioned handle secured to one end of the barrel, said handle comprising a hand grasping section having a pressure iiuid supply passage therein, a coupling section connecting the handle to the barrel, a third section carried by the hand grasping section, a cushion member of so-lid resilient rubber interposed between and vulcanized to the third and the coupling sections, respectively, for relieving the hand grasping section of vibrations in the operation of the tool, and a tubular member connected with the supply passage in the hand grasping section and extending into the coupling section through the cushion member for conveying pressure iiuid for operating the tool from the handle to the barrel, said cushion member maintaining the tubular member and third section out of contact with the coupling section and being exposed on the outer side of the tool for expansion laterally of the barrel, said tubular member being carried by the third section, and the hand grasping section being releasably secured to the third section, whereby the cushion member may be vulcanized to the third and the coupling sections while released from the hand grasping section.

2. In a portable pneumatic hammer having a barrel, a cushioned handle secured to the inner end of the barrel, said handle comprising spaced sections, one section coupling the handle to the barrel and having an opening over the inner end of the barrel and the other section providing a hand grasping portion having a pressure iiuid supply passage therein, a cushion member of solid resilient rubber interposed between and Vulcanized to said sections for relieving the hand grasping section of vibrations in the operation of the tool, and a tubular member connected with the supply passage in the hand grasping section and extending into the opening in the coupling section through the cushion member for conveying pressure uid for operating the tool from the handle to the barrel, said cushion member having an integral portion surrounding the end of the tubular member in the opening in the coupling section for compression in response to bending of the hand grasping section out of axial alignment with the barrel.

3. In a portable pneumatic hammer having a barrel and a hammering piston therein, a valve block seated on the inner end of the barrel and having valve means for controlling the supply of pressure uid to the barrel for reciprocating the piston, a cushioned handle secured to the inner end of the barrel and comprising, a hand grasping section having a pressure fluid supply passage therein, a coupling section screwed on the barrel over and against the valve block for clamping the same on the barrel, a third section releasably secured to the hand grasping section, a cushion member of solid resilient rubber interposed between and vulcanized to the third and coupling sections, respectively, for relieving the hand grasping section of vibrations in the operation of the tool, and a tubular member connected with the supply passage in the hand grasping section and extending into the coupling section through the cushion member for conveying pressure fluid for operating the tool from the handle to the barrel, said cushion member maintaining the tubular member and the third section out of contact with the coupling section and being exposed on the outer side of the tool for expansion laterally of the barrel, said tubular member being carried by said third section.

4. In a portable pneumatic hammer having a barrel, a cushioned handle secured to one end of the barrel, said handle comprising a hand grasping section having a pressure iiuid supply passage therein, a coupling section connecting the handle to the barrel, a third section releasably secured to the hand grasping section, a cushion member of resilient rubber interposed between and vulcanized to the third and coupling sections, respectively, to absorb vibrations imparted to the coupling section from the barrel, a tubular member carried by the third section and extending into the coupling section through the cushion member, said tubular member being connected with the supply passage for conveying pressure uid from the handle to the barrel, said cushion member having an integral flange portion interposed between the tubular member and the coupling section and a wear resisting surface carried by the flange portion for the tubular member.

5. In a portable pneumatic hammer having a barrel, a cushioned handle secured to one end of the barrel, said handle comprising a handgrasping section having a pressure iiuid supply passage therein, a coupling section connecting the handle to the barrel, a third section releasably secured to the hand grasping section, a vibration absorbing cushion member of solid resilient rubber interposed between and vulcanized to the third and coupling sections, respectively, and a tubular member carried by the third section and extending into the coupling section through the cushion member, said tubular member being connected with the supply passage for conveying pressure fluid from the handle to the barrel, said cushion member being exposed on the outer side of the handle and having its opening for the tubular member larger in diameter than the same, whereby the cushion member may expand laterally of the barrel in opposite directions.

6. In a portable pneumatic hammer having a barrel, a cushioned handle secured to one end of the barrel, said handle comprising a hand grasping section having a pressure iiuid supply passage therein, a coupling section connecting the handle to the barrel, a third section having a hollow lug to which the hand grasping section is releasably secured, a vibration absorbing cushion member of solid resilient rubber interposed between and vulcanized to the third and coupling sections, respectively, and a tubular member having a pressed i'lt in said lug and extending into the coupling section through the cushion member, said tubular member and said lug having communicating openings connected with the supply passage for conveying pressure fluid from the handle to the barrel through the tubular member.

7. In a portable pneumatic hammer having a barrel and a hammering piston therein, a valve block seated on the inner end of the barrel and containing a valve for controlling the supply of pressure fluid to the barrel for reciprocating the piston, a cushioned handle secured to the barrel over the valve block and comprising a hand grasping section having a pressure iluid supply passage therein, a coupling section connecting the handle to the barrel, a third section releasably secured to the hand grasping section, a vibration absorbing cushion member of solid resilient rubber interposed between and vulcanized to the third and coupling sections, respectively, a tubular member'carried by the third section and extending into the coupling section through the cushion member, the latter being connected to the supply passage for conveying pressure fluid from the handle to the barrel, said cushion member having an integral flange portion between the tubular and cushion members, and means providing an oil seal between the valve block and the adjacent ends of the flange and the tubular member.

8. In a portable impact tool having a. barrel, a

cushioned handle secured to one end of the barrel,v

said handle comprising a hand grasping section, a coupling section screwed on the barrel for connecting the handle thereto, a third section having screw threaded connection with the hand grasping section, and a cushion member of resilient rubber interposed between and vulcanized to the third and coupling sections, respectively, said thirdI and coupling sections having Wrench engaging portions, whereby said sections may be applied to and removed from the barrel andthe hand grasping section without straining the cushion member.

FRITHIOF P. FORSS. 

